OCI_ATTR_FNCODE returns OCI function codes. I can't find any OCI_ATTR_FNCODE references after oracle 8 documentation. Was it deprecated?
Oh. Yes. That's no more available. OCIUserCallBackRegister() can be used to register entry/exit callback functions for the OCI API using their function codes though. In case you want to trace. https://docs.oracle.com/en/database/oracle/oracle-database/19/lnoci/user-defined-callback-functions.html#GUID-7CC81F1D-0EB3-464A-B87F-CF4F18BCBA7C